Rapid prototyping describes various techniques for fabricating a three-dimensional prototype of an object from a computer model of the object. One technique is three-dimensional printing whereby a special printer is used to fabricate the prototype from a plurality of two-dimensional layers. In particular, a digital representation of a 3-D object is stored in a computer memory. Computer software sections the representation of the object into a plurality of distinct 2-D layers. A 3-D printer then fabricates a layer of material for each layer sectioned by the software. Together, the various fabricated layers form the desired prototype.
An apparatus to build a three-dimensional part from powder typically includes a powder supply and a build surface. Powder is transferred from the powder supply to the build surface in incremental layers. In one method of three-dimensional printing, layers of a powder material are deposited in a confined area. A binder solution is selectively deposited on each layer to produce regions of bound powder. A typical apparatus to deposit the binder is an inkjet-type printhead. The unbound powder is then removed to yield a three-dimensional part.